The Relationship Between Potential Occupational Sensitizing Exposures and Asthma: An Overview of Systematic Reviews.

OBJECTIVES: The aim was to identify, appraise, and synthesize the scientific evidence of the relationship between potential occupational sensitizing exposures and the development of asthma based on systematic reviews. METHODS: The study was conducted as an overview of systematic reviews. A systematic literature search was conducted for systematic reviews published up to 9 February 2020. Eligibility study criteria included persons in or above the working age, potential occupational sensitizing exposures, and outcomes defined as asthma. Potential occupational sensitizing exposures were divided into 23 main groups comprising both subgroups and specific exposures. Two reviewers independently selected studies, extracted study data, assessed study quality, and evaluated confidence in study results and level of evidence of the relationship between potential occupational sensitizing exposures and asthma. RESULTS: Twenty-seven systematic reviews were included covering 1242 studies and 486 potential occupational sensitizing exposures. Overall confidence in study results was rated high in three systematic reviews, moderate in seven reviews, and low in 17 reviews. Strong evidence for the main group of wood dusts and moderate evidence for main groups of mites and fish was found. For subgroups/specific exposures, strong evidence was found for toluene diisocyanates, Aspergillus, Cladosporium, Penicillium, and work tasks involving exposure to laboratory animals, whereas moderate evidence was found for 52 subgroups/specific exposures. CONCLUSIONS: This overview identified hundreds of potential occupational sensitizing exposures suspected to cause asthma and evaluated the level of evidence for each exposure. Strong evidence was found for wood dust in general and for toluene diisocyanates, Aspergillus, Cladosporium, Penicillium, and work tasks involving exposure to laboratory animals.

Historical Asbestos Measurements in Denmark-A National Database.

OBJECTIVES: Due to the long lag-time for health outcomes, historical asbestos exposure measurements are valuable to support assessments of associated occupational health effects, and also to assess time trends and effects of preventive measures. METHODS: Different sources of stored data were collated, assessed and refined to create a harmonized database on historical asbestos fibre concentrations measured in specific work tasks and different industries. The final database contains 9236 asbestos measurements from Danish workplaces collected from 1971 to 1997. RESULTS: The geometric mean of asbestos concentrations in different occupations and tasks ranged from 0.003 to 35 fibres cm-3. Highest concentrations were registered during handling of asbestos products in the construction services during the period 1981-1997. Although all the measured asbestos exposures without the use of respiratory equipment by the worker in the period of 1971-1997 exceeded the current 8-h time-weighted average exposure limit of 0.1 fibres cm-3, the majority of samples collected in the earlier period of 1971 to 1980 did not exceed the exposure limit of 2 fibres cm-3, which was in place at the time. All exposure data obtained from 1980 and onwards were found to be one seventh of the mean fibre concentrations in the previous measurement period. The impact of time shows a clear exponentially decreasing trend-line. CONCLUSIONS: Despite limitations in coverage of different occupations and tasks associated with the inventoried historical asbestos measurements, the data are helpful to identify specific work scenarios within an industry, where relatively high asbestos exposure levels may still occur or have occurred from 1971 to 1997.

Pyromellitic dianhydride (PMDA) may cause occupational asthma.

INTRODUCTION: Anhydrides are widely used as cross-linking agents in epoxy resins and alkyd production, for example, as coatings and adhesives in plastic products. Sensitisation to several anhydrides is known to cause occupational asthma. There are indications that the lesser known pyromellitic dianhydride (PMDA) can cause irritative respiratory symptoms and possibly asthma. We report three cases of workers from a plastic foil manufacturing plant, who developed asthma when exposed to PMDA during specific inhalation challenge (SIC). METHODS: SIC was performed over 2 days according to recommendations of European Respiratory Society. Lactose powder was used in control challenges and a mixture of 10% PMDA and 90% lactose powder in active challenges. RESULTS: All cases experienced a delayed decrease in forced expiratory flow in 1 s (FEV1) 4-12 hours after active challenge. FEV1 decreased by 19%, 15% and 16%, respectively. After 21 hours, FEV1 decreased by 24% in one worker. DISCUSSION: Respiratory symptoms after working hours may represent delayed work-related asthma. During SIC, the three patients developed lower respiratory symptoms and a delayed decrease in FEV1 which suggest sensitisation. The mechanism of anhydride-related asthma is not well understood. Anhydrides are known irritants and hence an irritative response cannot be excluded. The company improved ventilation and enforced the use of respiratory protection equipment, and finally phased out PMDA. Occupational workplace risk identification may help to identify exposures. SIC can contribute to improving working conditions, by identifying and confirming asthmogens in the environment.

[Work-up of asbestosis and estimation of asbestos exposure in an occupational context].

Asbestosis is interstitial lung fibrosis due to inhalation of asbestos fibres. Up to the ban of import in 1986, 0.7 mil tons had been used in Denmark. The diagnosis of asbestosis is a challenge because of long latency time and very few national occupational asbestos measurements. The cornerstone of exposure assessment is a thorough occupational history, investigation of asbestos content in products used, search for possible and relevant measurements of asbestos fibres in the air, and results of lung biopsies, if present. Although no definite lower limit of exposure can be defined, a cumulated exposure of > 10 fibre-years is a relevant measure for exposure defining the disease, as one fibre-year equals one asbestos fibre/cm3 air/occupational year.

Systemic sarcoidosis mimicking malignant metastatic disease.

We present a case of systemic sarcoidosis involving the liver, pancreas, lungs, mediastinal and intraabdominal lymph nodes and bones. Multiple organ system manifestations mimicked malignant metastatic disease. The diagnosis was established with clinical, radiological, and pathological findings after neoplasm was ruled out by pathological tests. The patient showed rapid symptom remission with systemic steroid treatment.

[Allergic rhinoconjunctivitis caused by occupational exposure to ginger]. / Allergisk rinokonjunktivitis pga. erhvervsmæssig udsættelse for ingefær.

We present a case report of occupational allergic rhinoconjunctivitis after exposure to dust from ginger-containing herbal medicine. The likelihood of an aetiological connection between exposure and the patient's symptoms was supported by a temporal association, positive specific IgE, positive histamine release test, positive prick test, and positive acoustic rhinometry test. Occupational allergy to ginger has rarely been reported. The cases described - including the one we present - suggest that work-related IgE-mediated allergy is associated with exposure to dry aerosols/dust.

[Working as a sandblaster can cause silicosis]. / Arbejde med sandblæsning kan give lungesilikose.

Silicosis is a common occupational disease worldwide. It is caused by the inhalation of crystalline silicon dioxide, i.e. silica. Quartz is a common form of silica and occurs in sandstone and granite. Occupational exposure can occur e.g. in mining, quarrying and sandblasting. The inhaled silica triggers an inflammatory response when phagocytosed which eventually causes fibrosis. We present a 45-year-old male Danish sandblaster who developed silicosis, and due to rapid decline in lung function received a lung transplant with an excellent result.

[Delayed asthma bronchiale due to epoxy resin]. / Astmatisk senreaktion efter kontakt med epoxy.

Epoxy resin is a low molecular weight agent, which can cause both acute and delayed allergic reactions. However, it is known causing skin reactions with direct or airborne contact. Rarely it can cause airway reactions like asthma bronchiale. We describe a case of a windmill worker who developed delayed asthma bronchiale due to airborne contact with epoxy resin.

[A small bird gives severe consequences]. / En lille fugl med alvorlige konsekvenser.

In this case we report how a 31 year-old woman developed hypersensitivity pneumonitis due to her budgerigar. The suspicion that her pet was the reason for her symptoms was confirmed by the finding of specific IgG antibodies against budgerigar proteins. Clinical studies demonstrated a restrictive lung disorder, increased lymphocytes in bronchoalveolar lavage and ground glass changes in high-resolution computed tomography. The patient's symptoms receded over the course of a few days after removal of the animal, and subsequent IgG levels fell.